Dimension stone is a type of natural stone that is used in construction as building facing, curbing, paving stone, monuments, and more. To ensure durability, material testers must test compressive strength according to ASTM C170.

Dimension stones are natural materials, meaning each stone varies in appearance and properties. This inherent variability can complicate engineering decisions, as no two stones are exactly alike. However, by following a standardized test method and adhering to a precise protocol for preparing stone test specimens, it’s possible to generate reliable data that helps mitigate these challenges. This approach ensures that engineering decisions are based on consistent, accurate information, allowing for more predictable and effective use of dimension stone in construction.

ASTM C170 helps material testers ensure durability and compare the differences in compressive strength between stone types. It includes guidance about selecting, preparing, and conditioning test specimens, but ASTM C1799 covers that process in more detail.

In this simple guide, we cover the basics of ASTM C170:

• What is dimension stone?
• Recommended equipment for ASTM C170
• ASTM C170 test preparation, procedure & results

What Is Dimension Stone?

Dimension stone is a natural stone that is quarried and cut into specific shapes and sizes for use in construction. It is valued for its durability, strength, and aesthetic appeal. Types of stone include:

• Granite: A strong, dense stone often used for countertops, flooring, and exterior cladding.
• Limestone: A softer, more porous stone used for facades, flooring, and decorative features.
• Marble: Known for its beauty and veining, used in high-end interiors, sculptures, and facades.
• Sandstone: A versatile, textured stone used in both interior and exterior applications.
• Slate: A fine-grained, durable stone often used for roofing, flooring, and wall cladding.

Here’s what you will need to test dimension stone according to ASTM C170.

Recommended Equipment for ASTM C170

A saw or core drill to cut test specimens from the sample, and an end grinder to ensure as true and parallel planes as possible.

An oven to dry test specimens; a desiccator to cool the specimens to room temperature before testing.

A scale to weigh specimens, and a caliper to measure specimen dimensions.

A water tank to immerse test specimens for wet conditioning.

A compression testing machine to apply compressive force to the dimension stone. Specifically, a Connected Compression Machine includes automatic controls and integrated testing software, leading to more reliable measurements and calculations – and more transparent results.

READ MORE: What Are Connected Material Testing Machines?

With this equipment, you’re ready to conduct a compressive strength test according to ASTM C170.

ASTM C170 Test Preparation, Procedure & Results

1. Select a representative sample of the true average of the type or grade of stone.
2. Prepare at least 5 specimens for each test condition (typically a minimum of 20 specimens):
   1. Cut test specimens into cubes or right cylinders with saw or core drill.
   2. Measure and record dimensions to calculate load-bearing area.
   3. Grind ends for flat load bearing surfaces.
   4. Mark load-bearing surfaces and direction of rift on each specimen.
3. For dry conditioning, dry specimens for at least 48 hours and ensure specimens weigh the same at the 46^th, 47^th, and 48^th
4. For wet conditioning, immerse specimens for 48 hours (up to 72 hours) and test within 5 minutes of removing them from the bath.
5. Conduct compressive strength test according to ASTM C39:
   1. Center the specimen in the testing machine.
   2. Apply initial seating load to hold specimen in place.
   3. Rotate contact plate to seat the spherical block.
   4. Apply load at a uniform rate not exceeding 100 psi/s until failure.
6. Record the maximum load applied to each specimen at failure and calculate the compressive strength.
7. Report results including stone type, specimen dimensions and orientations, conditioning procedures used, individual test results, average values, and standard deviations.

RELATED: Simple Guide to ASTM C39: Concrete Cylinder Compressive Strength Testing

Conclusion

ASTM C170 ensures material testers follow standard test methods for compressive strength testing of dimension stone. While you can follow this simple guide to get started, please review the current ASTM standard and other referenced standards for the most up-to-date protocols.

Forney has the machines, accessories, and software necessary for ASTM C170. Shop the Forney store today or find your machine.